Surprisingly, I had very little problem focusing. I was even using my Sigma 70-300mm APO lens mostly in the 200-300mm range too; my main concern, therefore, was vibration. Even with the low light, I was able to focus most of the time. I was even able to take a few shots handheld thanks to SR. Metering was not too bad either; I kept the camera at P most of the time. I could not take good photos with the M 50mm f/1.4 lens, however; guess I need to work on my low-light skills with that lens (or dump it and consider a 43mm limited :-))